To me these look like the he400 chassis, a new headband and an unknown driver. Hey Massdrop, can you comment on this and let us know what driver was selected? Thanks!
Since the driver is under NDA, measures kind of like the 400s driver, my best guess knowing how terrible HiFiMan stuff has been, (and no talk of driver matching) it's probably B-Stock drivers that HiFiMan isn't planning to use in regular production models.